Wilderness Medical Society Practice Guidelines for Spine Immobilization in the Austere Environment

WILDERNESS & ENVIRONMENTAL MEDICINE, 24, 241–252 (2013)

WILDERNESS MEDICAL SOCIETY PRACTICE GUIDELINES

Wilderness Medical Society Practice Guidelines for Spine Immobilization in the Austere Environment Robert Quinn, MD; Jason Williams, BS, NREMT-P; Brad Bennett, PhD, NREMT-P; Gregory Stiller, MD; Arthur Islas, MD; Seth McCord, MD From the Department of Orthopaedic Surgery, University of Texas Health Sciences Center, San Antonio, TX (Dr Quinn); EMS Academy (Mr Williams) and Department of Orthopaedic Surgery (Dr McCord), University of New Mexico, Albuquerque, NM; Military and Emergency Medicine Department, Uniformed Services University of the Health Sciences, Bethesda, MD (Dr Bennett); Department of Emergency Medicine, Sky Ridge Medical Center, Lone Tree, CO (Dr Stiller); and Department of Family and Community Medicine, Texas Tech Health Science Center, El Paso, TX (Dr Islas).

In an effort to produce best-practice guidelines for spine immobilization in the austere environment, the Wilderness Medical Society convened an expert panel charged with the development of evidence-based guidelines for management of the injured or potentially injured spine in an austere (dangerous or compromised) environment. Recommendations are made regarding several factors related to spinal immobilization. These recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks or burdens for each factor according to the methodology stipulated by the American College of Chest Physicians. A treatment algorithm based on the guidelines is presented. Key words: spinal injury, spinal trauma, spinal immobilization, cervical spine injury, cervical spine immobilization, cervical spine clearance

Introduction Techniques for immobilization and extrication of the patient with a real or potential spine injury have been implemented for decades. These techniques use practical but not systematic approaches driven by a wellintentioned aversion to inflicting further serious injury. Furthermore, there is little evidence to support the effectiveness or necessity of these techniques. Prehospital care of the spine may represent one of the more illustrative examples of clinical medicine being driven more by medicolegal implications than sound clinical or scientific evidence. Although the high cost (in terms of both dollars and resources) of defensive medicine in this regard may or may not be justified in the civilized environment, in the austere (dangerous or compromised) environment any decision to immobilize a spine is directly associated with the potential for further injury to the patient as well as rescuers. When an injured, or potentially injured, patient is located in a compromised environment, rescuers will often literally be risking their Corresponding author: Robert Quinn, MD, Department of Orthopaedic Surgery, University of Texas Health Science Center San Antonio, Mail Code 7774, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900 (e-mail: [email protected]).

lives to both avoid further injury to the patient and effect a safe extrication. Under these circumstances, the need for sound evidence in clinical decision making is paramount. In an effort to develop proper guidelines for spinal immobilization in the austere environment, based on best existing evidence, an expert panel was convened to develop evidence-based guidelines. Methods A panel with experts in the field was convened at the Wilderness Medical Society annual meeting in Snowmass, CO, in July 2011. Members were selected from multiple professional backgrounds based on clinical interest or research experience. The panel includes 2 orthopaedic surgeons, 2 experienced academic emergency medical technicians (EMTs; 1 military and 1 civilian), 1 emergency physician, and 1 family practitioner with sports medicine fellowship training. Relevant articles were identified through the PUBMED and Cochrane Collaboration databases using key word searches with the appropriate terms corresponding to each topic. Peer-reviewed studies related to spine immobilization including randomized controlled trials, observational studies, and case series were reviewed,

242

Quinn et al

and the level of evidence supporting the conclusions was assessed. Abstract-only studies were not included. Conclusions from review articles were not considered in the formulation of recommendations but are cited below in an effort to provide context. When no relevant studies were identified, the expert panel recommendation was based on risk vs benefit perceptions derived from patient care experience. The panel used a consensus approach to develop recommendations regarding management of spinal injuries in the wilderness. These recommendations have been graded based on clinical strength as outlined by the American College of Chest Physicians (ACCP; Table).1 Scope of the Problem The incidence of spinal cord injury (SCI) in the United States is estimated at 40 to 50 cases per million people per year, representing 3% of hospital trauma admissions.2 Two to five per cent of patients with SCI will demonstrate neurologic deterioration regardless of the effectiveness of prehospital care, based on the pathophysiology of the injury itself (progressive neurologic ischemia, spinal cord edema, etc).3,4 Authors have noted an improvement in neurologic status of SCI patients arriving in emergency departments during the past 30 years. During the 1970s, 55% of patients referred to SCI centers arrived with complete neurologic lesions, whereas in the 1980s that number

decreased to 39%.5 This improvement in neurologic status has been attributed to emergency medical services (EMS) initiated in the early 1970s. However, there is no evidence to support the belief that this improvement has anything to do with EMS protocols. Certainly, improvements in automobile safety and design, along with compulsory seat belt use laws, are at least partially responsible for these observations. Review of data from the National Automotive Sampling System data files between 1995 and 2001 revealed 8412 cases of cervical spine injury.6 Approximately half (44.7%) were unrestrained occupants, and the remainder consisted of belted only (38.2%), airbag only (8.8%), and both (8.4%) restraint systems. It is important to interject some a priori clarity to the publication of these guidelines. Many articles have been repeatedly quoted in the literature as offering case evidence of neurologic deterioration in the presence of SCI secondary to inadequate prehospital immobilization.7–13 Careful review of these cases, however, reveals that virtually all represent missed or late diagnoses after hospital admission, or deterioration that occurred while under treatment for a known diagnosis. The focus of these guidelines is to present an evidence-based approach to prehospital care that minimizes the possibility of neurologic deterioration in the presence of an existing or potential SCI from the time of extrication to arrival at a medical facility.

Table. ACCP classification scheme for grading evidence and recommendations in clinical guidelines1 Grade

Description

Benefits vs risks and burdens

1A

Strong recommendation, high-quality evidence

Benefits clearly outweigh risks and burdens or vice versa

1B

Strong recommendation, moderate-quality evidence

Benefits clearly outweigh risks and burdens or vice versa

1C

Strong recommendation, lowquality or very low quality evidence Weak recommendation, highquality evidence

Benefits clearly outweigh risks and burdens or vice versa Benefits closely balanced with risks and burdens

2B

Weak recommendation, moderate-quality evidence

Benefits closely balanced with risks and burdens

2C

Weak recommendation, lowquality or very low quality evidence

Uncertainty in the estimates of benefits, risks and burden; benefits, risk and burden may be closely balanced

2A

ACCP, American College of Chest Physicians; RCT, randomized controlled trial.

Methodological quality of supporting evidence RCTs without important limitations or overwhelming evidence from observational studies RCTs with important limitations or exceptionally strong evidence from observational studies Observational studies or case series

RCTs without important limitations or overwhelming evidence from observational studies RCTs with important limitations or exceptionally strong evidence from observational studies Observational studies or case series

WMS Practice Guidelines for Spine Immobilization in the Austere Environment Spinal immobilization itself is not a benign procedure. In addition to the risk of further injury to the patient as a consequence of increasing the danger of rescue, spinal immobilization itself is associated with documented risks and rather extreme discomfort. Although the expert panel was unable to identify a single well-documented case in the literature of prehospital neurologic deterioration as a direct consequence of improper or inadequate immobilization, many cases have documented severe morbidity, and even mortality, secondary to immobilization itself.2,14–25 For the purpose of developing proper guidelines for spinal immobilization in a dangerous environment, it is important to recognize and attempt to differentiate 5 types of spinal injury scenarios: 1) an uninjured spine, 2) a stable spine injury without existing or potential neurologic compromise, 3) an unstable, or potentially unstable, spine injury without apparent neurologic compromise, 4) an unstable spine injury with neurologic compromise, and 5) a severely injured patient with unknown spinal injury status. If immobilization is to be used, it would be indicated for numbers 3, 4, and 5. ‘‘Clearing the spine’’ has many definitions depending on circumstances and training level of the provider, and is generally regarded as more vernacular than academic. For instance, depending on the professional circle, a cleared patient may have no spine injury, have a low enough probability of injury to not need a board or collar and not need radiographic imaging based on decision rule criteria (eg, National Emergency X-radiography Utilization Study [NEXUS]), or have had radiographic imaging with no demonstrable injury. Further, some wilderness medicine educational organizations teach that clearing the spine is performed only for evacuation purposes, and should then be followed by formal evaluation by an advanced medical provider. For the purpose of this manuscript, clearing the spine refers to the process of either correctly identifying number 1 or 2 above, or perhaps more importantly ruling out numbers 3, 4, and 5. A patient may have symptoms or physical findings associated with a spinal injury of no acute consequence (number 2), including sprains, strains, and even mild fractures (eg, spinous process or mild compression fracture). Some of these injuries may even result in longer-term symptoms that may require medical attention at a later date (eg, a strain that develops chronic symptoms amenable to medication or physical or massage therapies). If a provider clears the spine, the important distinction is that the injury is and will continue to be in the number 2 category with a probability less than 1% of missing a number 3, 4, or 5 category injury.

243

Results Guidelines related to spinal immobilization, the evidence supporting them, and their recommendation grades are described below. PREFERRED POSITION FOR THE INJURED SPINE Although no studies have specifically evaluated an optimal generic position for the injured spine, clinical evidence (derived from imaging and patient care experience with traction, manipulation, and operative reduction) would strongly suggest that neutral alignment is preferred. Recommendation: Neutral alignment should be restored and maintained with light to moderate manual cervical traction during extrication, unless such a maneuver is met with resistance, increased pain, or new or worsening neurologic deficit. Recommendation grade: 1C. METHODS OF EXTRICATION WITH POSSIBLE CERVICAL SPINE INJURY Shafer and Naunheim26 published a study analyzing neck motion during extrication from a mock automobile using an infrared 6-camera motion-capture system. Compared with extrication by experienced paramedics, allowing an individual to exit the vehicle under his own volition with cervical collar in place resulted in the least motion of the cervical spine. A radiographic comparison showed superior immobilization of the normal cervical spine during extrication from an automobile with a Kendrick extrication device (KED) plus Philadelphia collar compared with short board, tape, and collar.27 Similar benefit has been demonstrated in other studies with the KED as well as similar devices.28–30 Recommendation: Patients requiring extrication, when the cervical spine cannot be cleared before extrication, should be placed in a cervical collar and allowed to exit the situation under their own volition if alert and reliable. Otherwise extrication should be performed with a KED (or similar device) plus cervical collar, and the immobilized patient moved in a sitting position onto a long spine board, vacuum mattress, or similar device. Recommendation grade: 1C. MOVING THE PATIENT WITH REAL OR POTENTIAL SPINE INJURY Boissy et al31 demonstrated superior stabilization of the entire spine with lift and slide transfer to a backboard compared with log roll. This study also compared 2 methods of providing additional manual cervical spine stabilization relative to maintaining simultaneous stabilization of the thoracolumbar spine, the head squeeze and

244

Quinn et al

Figure 1. Demonstration of trap squeeze technique for manual cervical spine stabilization.

the trap squeeze. With the head squeeze maneuver, the lead rescuer lets the patient’s head rest in the palms, hands on both sides of the head with fingers placed so that the ulnar fingers can grab the mastoid process below and the second and third fingers can apply a jaw thrust if necessary. With the trap squeeze, the rescuer grabs the patient’s trapezius muscles on either side of the head with his or her hands (thumbs anterior to the trapezius muscle) and firmly squeezes the head between the forearms with the forearms placed approximately at the level of the ears (Figure 1). The trap squeeze was superior to head squeeze in this study, particularly with simulation of an agitated patient. The superiority of the lift and slide transfer over the log roll in providing stabilization of the entire spine has also been demonstrated in other studies.32,33 Recommendation: The lift and slide transfer with trap squeeze is preferred to the log roll when transferring patients to and from a backboard. Recommendation grade: 1C. EFFECTIVENESS OF SPINAL IMMOBILIZATION IN REDUCING THE INCIDENCE OF NEUROLOGIC SEQUELAE A Cochrane review found no randomized controlled trials of spinal immobilization. The authors of that review concluded that the effect of spinal immobilization on mortality, neurologic injury, spinal stability, and adverse effects in trauma patients remains uncertain.2 Because airway obstruction is a major cause of preventable death in trauma patients and spinal immobilization can contribute to airway compromise, the authors also concluded that the possibility that immobilization may increase morbidity and mortality cannot be excluded.

Hauswald et al34 reported a retrospective review of all patients reporting to 2 university hospitals with acute blunt traumatic spinal or spinal cord injuries transported directly from the injury site to the hospital. None of 120 patients treated at one university hospital had spinal immobilization during transport, whereas all 334 patients treated at the other university did. There was less neurologic disability in the patients who were not immobilized (odds ratio, 2.03; 95% confidence interval, 1.03 to 3.99; P ¼ .04). Recommendation: Spinal immobilization should be considered in patients with evidence of spinal injury, including those with neurologic injury, and those patients who have experienced severe trauma and are unconscious or exhibit altered mental status. Recommendation grade: 2C. EFFECTIVENESS OF THE CERVICAL COLLAR IN IMMOBILIZATION OF THE CERVICAL SPINE Although use of the cervical collar is considered the gold standard in immobilization of the cervical spine, little evidence exists to support its effectiveness. An assumption exists that the neutral anatomic position is desired with an injured spine, and that the cervical collar accomplishes this goal. However, one study demonstrated that more than 80% of adults require 1.3 to 5.1 cm of occipital padding in addition to a cervical collar to maintain the cervical spine in the neutral position relative to the torso, dependent on physical characteristics and muscle development.35 A separate assumption exists that the cervical collar restricts motion of the cervical spine. However, using a cadaver model, Horodyski et al36 concluded that using a

WMS Practice Guidelines for Spine Immobilization in the Austere Environment cervical collar was better than no immobilization, but did not effectively reduce motion in an unstable spine model. Another cadaveric study analyzed cervical motion with no collar and with 3 different cervical collar types.33 Although there was a decrease in the amount of motion generated in every plane of motion as a result of wearing each of the 3 collars, none of the changes proved to be significantly different. Holla37 showed that a rigid cervical collar combined with a backboard reduced cervical motion to 34% of normal. Use of head blocks and a backboard reduced motion to 12% of normal. Addition of a rigid cervical collar to the use of head blocks provided no added immobilization benefit but did limit mouth opening. These results have been somewhat contradicted by Podolsky et al,38 who demonstrated in a similar study that neither collars alone nor sandbags and tape provided satisfactory restriction of cervical spine motion. In their study, addition of a rigid cervical collar to the sandbags and tape resulted in a statistically significant reduction in neck extension. Lador et al,39 using a cadaveric model, demonstrated cervical distraction at the site of injury with the use of a rigid collar, as well as creation of a pivot point in the cervical spine where the collar meets the skull and shoulders. Others have also demonstrated abnormal separation between vertebrae with the use of cervical collars in the presence of a dissociative injury.40 Independent of whether or not cervical collars are effective, their use may be associated with complications related to the collar itself. Cervical orthoses can increase the risk of aspiration and impede the ability to establish an adequate airway. Additionally, these devices have been shown to directly compromise respiration. Ay et al20 demonstrated statistically significant decreases in forced expiratory volume in 1 second (FEV1) and forced vital capacity with both the KED and long spinal backboard. Another study showed a 15% decrease in FEV1 with a cervical collar and backboard, and noted that respiratory restriction was more pronounced with age.12 Others have demonstrated similar findings.17,18,20 Cervical collars have also been associated with elevated intracranial pressure,41–44 and pressure ulceration associated with the use of rigid cervical collars has been well documented.45–48 Although the expert panel remains unaware of any specific cases of documented neurologic deterioration occurring secondary to absent or inadequate prehospital immobilization, many cases of documented neurologic deterioration, and even death, have now been reported with the use of a cervical collar in patients with ankylosing spondylitis.21,22 In these patients, the rigid collar places the fragile cervical spine in a compromised position and should be considered contraindicated. When properly applied, an improvised SAM splint cervical collar can be as effective as a Philadelphia collar.49

245

Recommendation: The cervical collar (or improvised equivalent) should be considered one of several tools available to aid in immobilization of the cervical spine. It should not be considered adequate immobilization in and of itself, nor should it be considered necessary if adequate immobilization can be accomplished by other means, or if the presence of the collar in itself compromises emergent patient care. Recommendation grade: 2B. Recommendation: Use of the cervical collar is contraindicated in ankylosing spondylitis. Patients with suspected injury should have their neck supported in a position of comfort. Recommendation grade: 1B. EFFECTIVENESS OF THE BACKBOARD Several studies have demonstrated that a vacuum mattress provides significantly superior spine stability, increased speed of application, and markedly improved patient comfort when compared with a backboard.50–55 Vacuum mattress immobilization of the potentially injured spine is the current recommendation of the International Commission for Mountain Emergency Medicine.56 Recommendation: Vacuum mattress provides superior immobilization, with or without a standard cervical collar, and improved patient comfort (with corresponding decreased risk of pressure sores) and is preferred over a backboard for immobilization of either the entire spine or specific segments of concern. Recommendation grade: 1C. IMMOBILIZING THE CERVICAL SPINE Anderson et al57 have performed a meta-analysis of data related to clinical decision making concerning the use of immobilization of the asymptomatic cervical spine in blunt trauma patients. Data were derived from both in-hospital and prehospital settings. Their analysis revealed that an alert, asymptomatic patient without a distracting injury or neurologic deficit who is able to complete a functional range-of-motion examination may safely avoid cervical spine immobilization without radiographic evaluation (sensitivity, 98.1%; negative predictive value, 99.8%). NEXUS prospectively evaluated 5 variables in selected emergency department patients with blunt trauma: no midline cervical tenderness, no focal neurologic deficits, normal alertness, no intoxication, and no painful or distracting injury.58 Approximately 34,000 patients were evaluated, and cervical spine injuries were identified in 818 patients, 578 of which were clinically significant. All but 8 of the 818 patients were identified using the criteria (sensitivity, 99.0%; specificity, 12.9%; negative predictive value, 99.8%; and positive predictive value, 2.7%). Only 2 of the 8 had a clinically significant injury, one of which required surgery.

246 Domeier et al59 prospectively collected EMS data on 8975 patients with regard to 5 prehospital clinical criteria—altered mental status, neurologic deficit, spine pain or tenderness, evidence of intoxication, or suspected extremity fracture—the absence of which identifies prehospital trauma patients without a significant spine injury. They identified 295 patients with spine injuries (3.3%). Spine injury was identified by the prehospital criteria in 280 of 295 (94.4%). The criteria missed 15 patients. Thirteen of 15 had stable injuries (stable compression or vertebral process injuries). The remaining 2 would have been captured by more accurate prehospital evaluation. A similar prospective study with the same criteria collected data on 13,483 patients.60 Sensitivity of the EMS protocol was 92%, resulting in nonimmobilization of 8% of the patients with spine injuries, none of which experienced neurologic compromise. Maine has used a prehospital selective spine assessment protocol since 2002. Patients with qualified mechanism of injury (axial load, blunt trauma, motor vehicle collision, adult fall from standing height) are not immobilized if they are reliable (no intoxication or altered mental status), have no distracting injury, have a normal neurologic examination, and have no spine pain or tenderness. During one 12-month study period only 1 patient with an unstable spine fracture and 19 patients with stable fractures were found to have been not immobilized by the protocol in approximately 32,000 trauma encounters.61 The protocol had a sensitivity of 94.1%, negative predictive value of 99.9%, specificity of 59.3%, and positive predictive value of 0.1%. The single unstable spine injury occurred in an 86-year-old woman who injured her back while moving furniture 1 week before calling EMS and had a T6-T7 subluxation requiring fixation without neurologic injury. Elderly patients (465 years of age) represented the largest number of stable spine fractures without neurologic compromise, but also demonstrate a higher risk of complications (pain, pressure sores, respiratory compromise) from spinal immobilization. Further data from the same study population published separately revealed that 1301 patients of 2220 were immobilized on the basis of the protocol: 416 (32%) were unreliable, 358 (28%) were considered to have distracting injuries, 80 (6%) had an abnormal neurologic examination, and 709 (54%) had spine pain or tenderness.62 Of the 2220 patients, only 7 acute spine fractures were identified, of which all were appropriately immobilized. Studies have also validated the prehospital use of the Canadian C-spine protocol.63–71 This protocol investigates 3 questions relevant to whether or not a patient requires cervical spine radiographs: 1) is there a high-

Quinn et al risk factor present (age older than 65, dangerous mechanism, paresthesias)?; 2) is there a low-risk factor present that allows safe assessment of range of motions (simple rear-end motor vehicle accident, ambulatory at any time since injury, sitting position in the emergency department, delayed onset of neck pain, absence of midline cervical spine tenderness)?; and 3) is the patient able to actively rotate the neck 45o to the left and right? In one study, the NEXUS criteria were compared with the Canadian C-spine criteria by 394 physicians evaluating 8283 patients, with an overall incidence of 169 (2%) of clinically important spine injuries.69 The Canadian C-spine rule was more sensitive (99.4% vs 90.7%; P o .001) and more specific (45.1% vs 36.8%; P o .001) at detecting spine injuries. A study of 6500 patients evaluated the relationship between mechanism of injury and spinal injury.60 The authors concluded that the mechanism of injury does not affect the ability of clinical criteria to predict spinal injury. It should come as no surprise that this is the case and that no specific mechanism of injury will prove predictive in a meaningful capacity. There are certainly many cases in which minimal trauma can result in profound cervical spine injury with neurologic deficit (eg, an elderly patient after a minor fall). On the other hand, individuals often escape serious injury even after high-energy trauma. Konstantinidis et al72 reported on 101 evaluable patients with cervical spine injury. Distracting injuries were present in 88 patients (87.1%). Only 4 patients (4.0%) had no pain or tenderness on the initial examination of the cervical spine. All 4 patients had bruising and tenderness to the upper anterior chest. None of these 4 experienced neurologic sequelae or required surgical stabilization or immobilization. Recommendation: Appropriately trained personnel, using either the NEXUS criteria or the Canadian Cspine rule, can safely and effectively make decisions in the prehospital setting about whether or not a cervical spine should be immobilized. Recommendation grade: 1A. PENETRATING TRAUMA Blunt trauma to the spine is far more common than penetrating trauma. Although penetrating trauma is more common in a military than a civilian setting, blunt trauma is still the predominant mechanism of spine injury in the military setting. One study of 598 service members who sustained spinal injury showed 66% were the result of blunt trauma, 28%, penetrating trauma, and 5%, combined.73 Clinically significant spinal injury is rare in the setting of a stab wound, but not uncommon

WMS Practice Guidelines for Spine Immobilization in the Austere Environment after a gunshot wound (GSW).74 Neurologic deficit from penetrating assault is generally established and final at presentation.25,75,76 In the civilian setting, where GSWs are predominately low-velocity, spinal instability rarely occurs. Dubose et al77 reviewed 4204 patients sustaining GSWs to the head, neck, and torso in a civilian setting. Of these, 327 (7.8%) had bony spinal column injury. None of the 4204 patients demonstrated spinal instability, and only 2 of 327 (0.6%) required any form of operative intervention for decompression. They concluded that routine spinal imaging and immobilization is unwarranted in examinable patients without symptoms consistent with spinal injury. Lustenberger et al78 reported similar findings. High-velocity penetrating injury of the cervical spine is associated with a high incidence of major vascular injury and airway injury requiring advanced airway protection. Cervical spine immobilization has been associated with a higher incidence of morbidity, and even mortality, when used in the presence of penetrating cervical trauma.14–16,19,23 Similar findings have been demonstrated in thoracic injuries.25 Haut et al16 evaluated 45,284 patients with penetrating trauma and showed overall mortality to be twice as high in spineimmobilized patients (14.7% vs 7.2%; P o .001). In their study, the number needed to treat with spine immobilization to potentially benefit 1 patient was 1032, and the number needed to harm with spine immobilization to potentially contribute to 1 death was 66. The Committee on Tactical Combat Casualty Care currently recommends a balanced approach to cervical spine precautions when a significant mechanism of injury exists but there is a need to rapidly extract the casualty away from directed action on the battlefield during care under fire.79,80 The Prehospital Trauma Life Support Executive Committee has performed and published a systematic review of prehospital spine immobilization for penetrating trauma.76 They concluded that there are no data to support routine spine immobilization in patients with penetrating trauma to the cranium, neck, or torso. Recommendation: Spinal immobilization should not be performed in the presence of penetrating trauma Recommendation grade: 1B. Discussion The most frequently cited articles of missed spine injuries resulting in neurologic deterioration largely reference situations that occurred after presentation to the emergency department.7,8,13 Many of these cases had a recognized spine injury with neurologic deterioration

247

occurring as a result of nonoperative treatment, which at the time was standard of care. In fact, the article by Bohlman8 is considered a landmark paper in the orthopaedic literature, and the patients described formed the foundation for improved spinal injury care in the form of operative intervention. In the preponderance of the other reported cases, neurologic deterioration occurred because of a failure to recognize and adequately image patients in circumstances in which a high degree of suspicion of spinal injury should have been present, including 2 patients13 who sustained neurologic injury after surgery for a traumatized aorta. Davis et al7 reported 34 cases of missed cervical spine injuries (4.6%) in 740 trauma patients, 29% of whom experienced permanent neurologic sequelae. Thirty-one of 34 had inadequate or misinterpreted plain x-rays in the emergency department. Review of the elements of these cases presented in the paper would indicate that none of the patients for whom adequate data were provided would have passed either the NEXUS or Canadian C-spine criteria. In the few cases reported in which neurologic deterioration occurred in the prehospital setting, there is a presumption that these injuries were the result of inappropriate handling and lack of immobilization. Given the rarity of these types of reports, the current authors would submit, in light of recent evidence cited in this paper and elsewhere, that these episodes of neurologic deterioration are more likely a result of the injury itself. The concept of spinal immobilization has been predicated entirely on philosophical, theoretical, and medicolegal grounds, and the justification for its use remains unchanged despite more than 4 decades of widespread use. Despite a lack of evidence clearly supporting spinal immobilization and an absence of documented cases of neurologic deterioration as a result of inadequate immobilization, and in the face of accumulating data challenging both the philosophical and theoretical grounds of immobilization, no randomized controlled trials have yet been performed in an attempt to validate its ongoing use or stratify any risk-benefit ratio. In the urban setting, the routine use of spinal immobilization likely adds little to improve the care of the injured patient, but correspondingly likely accounts for little harm to the patient (in the absence of penetrating trauma) or first responders. The financial harm to the system (if indeed there is little evidence to support routine use) is likely enormous, measured in both direct (expense of increasing the time and complexity of extrication as well as unnecessary tests and procedures) and indirect costs (inadvertently ‘‘validating’’ subsequent medicolegal claims of spine injury). Conversely, the routine use of spinal immobilization in the austere environment not only increases the

248

Quinn et al

financial cost of rescue operations, but also greatly increases the time, logistics, and complexity of the operation, thereby also exacting a cost in terms of increased morbidity and mortality to not only the patient but rescue personnel as well. In the austere environment, the goal of spinal assessment and care should not be to definitively rule out or recognize all forms of spine injury. Rather, the goal should be to minimize the risk of missing or exacerbating a potentially unstable spine injury. The risk of missing such an injury should be appropriately calibrated against the risk of exposing rescuers to the potential for serious injury or causing further injury to the patient beyond that which occurred during the index traumatic event. In this context, it would appear that the NEXUS criteria and components of the Canadian C-spine rule are overly restrictive, particularly with regard to the mechanism of injury, when used in the austere environment to evaluate cervical spine injury. Although similar algorithms have not been developed for the thoracolumbar spine, one could argue that similar rules and conditions would be appropriately applicable.

It is fortuitous that the vacuum splint has become popular in the rescue environment. Not only is this device portable and rapidly deployable but it appears quite likely to provide superior spine immobilization in addition to its other packaging and evacuation benefits, not the least of which is enhanced patient comfort and a decrease in the likelihood of complications associated with a cervical collar and backboard. After careful and meticulous review of the literature, and in combination with the collective expertise of the authors, we recommend a treatment algorithm as outlined in Figure 2. Patients with isolated penetrating trauma should not receive spinal immobilization. However, definitive spinal evaluation should be performed on arrival at an appropriate medical center. When patients have sustained blunt trauma, with or without concomitant penetrating trauma, the mechanism of injury must be evaluated as it relates to the overall context of the patient and scene. Judgment regarding the likelihood of associated spinal injury should be individualized, as no reasonable guidelines are practical given

Figure 2. Recommendations for spine clearance and immobilization in the austere environment. GCS, Glasgow Coma Scale.

WMS Practice Guidelines for Spine Immobilization in the Austere Environment the wide and disparate combinations of trauma and injury. As previously discussed, given the appropriate circumstances, severe spine trauma can result with minimal trauma (particularly in the elderly) yet patients can often escape serious injury after the most dramatic trauma. If the patient is suspected of having a serious spinal injury but the spine cannot be reliably evaluated (severe injury, altered mental status, or significant distracting injury), the spine should be immobilized. The term severe injury is somewhat subjective but has been defined elsewhere as abnormal vital signs (systolic blood pressure o 90 mm Hg or respiratory rate outside of the range of 10 to 24 breaths/min).81 All patients with evidence of neurologic deficit should be immobilized. The definition of distracting injury should be considered in the same context as mechanism of injury and individualized accordingly. If the patient has experienced a trauma suspicious for spinal injury and the spine can be reliably evaluated, responders should evaluate for significant spine pain and tenderness (Z7/10). If neither is present, immobilization is not indicated. If spine pain or tenderness is present, but o7/10, the patient should be asked to demonstrate spinal range of motion within the limits of reasonable tolerance. If the patient can voluntarily flex, extend, and rotate 451 in each plane, immobilization is not necessary, but definitive evaluation should be performed on arrival at an appropriate medical center. If these maneuvers cannot be performed, the patient should be immobilized. Deciding whether or not to immobilize the spine using this algorithm can be safely accomplished by practitioners with at least a basic working knowledge of the fundamental elements. That is, the practitioner should be able to recognize degrees of major trauma, identify mechanisms of injury with the potential to cause spinal injury, perform a basic physical examination of the spine and neurologic system, and recognize distracting injuries. Although the preponderance of literature concerns the cervical spine, particularly as it relates to the Canadian C-spine and NEXUS protocols, much (particularly historical literature) refers to the entire spine. Although by its nature the cervical spine is certainly more prone to injury than the thoracolumbar spine, and the potential consequences are perhaps more devastating, injuries throughout the spine occur by similar mechanisms of injury and share similar pathophysiology and similar potential for neurologic injury. The authors believe that the discussions set forth in this manuscript, including the algorithm outlined in Figure 2, pertain to the entire spine, except when specifically indicated otherwise.

249

Conclusions Limited evidence supports the current rationale for stabilizing the potential spine injury in the austere environment. The authors believe that the proposed algorithm offers the best compromise between unnecessary immobilization and the risk of causing further damage in the presence of spinal injury, recognizing that both have the propensity to result in further injury to the patient and rescuers in the austere environment. Although these guidelines cover many of the relevant issues related to spine injury and immobilization, questions remain that should serve as the focus for future research.

References 1. Guyatt G, Gutterman D, Baumann MH, et al. Grading strength of recommendations and quality of evidence in clinical guidelines. Chest. 2006;129:174–181. 2. Kwan I, Bunn F, Roberts I. Spinal immobilisation for trauma patients. Cochrane Database Syst Rev. 2001(2): CD002803. 3. Farmer J, Vaccaro A, Albert TJ, Malone S, Balderston RA, Cotler JM. Neurologic deterioration after cervical spinal cord injury. J Spinal Disord. 1998;11:192–196. 4. Marshall LF, Knowlton S, Garfin SR, et al. Deterioration following spinal cord injury. A multicenter study. J Neurosurg. 1987;66:400–404. 5. [No authors listed]. Cervical spine immobilization before admission to the hospital. Neurosurgery. 2002;50(3 Suppl): S7–17. 6. Claytor B, MacLennan PA, McGwin G Jr, Rue LW 3rd, Kirkpatrick JS. Cervical spine injury and restraint system use in motor vehicle collisions. Spine. 2004;29:386–389; discussion Z2. 7. Davis JW, Phreaner DL, Hoyt DB, Mackersie RC. The etiology of missed cervical spine injuries. J Trauma. 1993;34:342–346. 8. Bohlman HH. Acute fractures and dislocations of the cervical spine. An analysis of three hundred hospitalized patients and review of the literature. J Bone Joint Surg Am. 1979;61:1119–1142. 9. Jeanneret B, Magerl F, Ward JC. Overdistraction: a hazard of skull traction in the management of acute injuries of the cervical spine. Arch Orthop Trauma Surg. 1991;110: 242–245. 10. Prasad VS, Schwartz A, Bhutani R, Sharkey PW, Schwartz ML. Characteristics of injuries to the cervical spine and spinal cord in polytrauma patient population: experience from a regional trauma unit. Spinal Cord. 1999;37:560–568. 11. Reid DC, Henderson R, Saboe L, Miller JD. Etiology and clinical course of missed spine fractures. J Trauma. 1987;27:980–986. 12. Totten VY, Sugarman DB. Respiratory effects of spinal immobilization. Prehosp Emerg Care. 1999;3:347–352.

250 13. Toscano J. Prevention of neurological deterioration before admission to a spinal cord injury. Paraplegia. 1988;26: 143–150. 14. Vanderlan WB, Tew BE, McSwain NE Jr. Increased risk of death with cervical spine immobilisation in penetrating cervical trauma. Injury. 2009;40:880–883. 15. Stuke LE, Pons PT, Guy JS, Chapleau WP, Butler FK, McSwain NE. Prehospital spine immobilization for penetrating trauma-review and recommendations from the Prehospital Trauma Life Support Executive Committee. J Trauma. 2011;71:763–770. 16. Haut ER, Kalish BT, Efron DT, et al. Spine immobilization in penetrating trauma: more harm than good? J Trauma. 2010;68:115–121. 17. Bauer D, Kowalski R. Effect of spinal immobilization devices on pulmonary function in the healthy, nonsmoking man. Ann Emerg Med. 1988;17:915–918. 18. Schafermeyer RW, Ribbeck BM, Gaskins J, Thomason S, Harlan M, Attkisson A. Respiratory effects of spinal immobilization in children. Ann Emerg Med. 1991;20:1017–1019. 19. Ramasamy A, Midwinter M, Mahoney P, Clasper J. Learning the lessons from conflict: pre-hospital cervical spine stabilisation following ballistic neck trauma. Injury. 2009;40:1342–1345. 20. Ay D, Aktas- C, Yes-ilyurt S, Sankaya S, Cetin A, Ozdo˘gan ES. Effects of spinal immobilization devices on pulmonary function in healthy volunteer individuals. Ulus Travma Acil Cerrahi Derg. 2011;17:103–107. 21. Thumbikat P, Hariharan RP, Ravichandran G, McClelland MR, Mathew KM. Spinal cord injury in patients with ankylosing spondylitis: a 10-year review. Spine (Phila Pa 1976). 2007;32:2989–2995. 22. Clarke A, James S, Ahuja S. Ankylosing spondylitis: inadvertent application of a rigid collar after cervical fracture, leading to neurological complications and death. Acta Orthop Belg. 2010;76:413–415. 23. Vanderlan WB, Tew BE, Seguin CY, et al. Neurologic sequelae of penetrating cervical trauma. Spine (Phila Pa 1976). 2009;34:2646–2653. 25. Brown JB, Bankey PE, Sangosanya AT, Cheng JD, Stassen NA, Gestring ML. Prehospital spinal immobilization does not appear to be beneficial and may complicate care following gunshot injury to the torso. J Trauma. 2009;67:774–778. 26. Shafer JS, Naunheim RS. Cervical spine motion during extrication: a pilot study. West J Emerg Med. 2009;10: 74–78. 27. Howell JM, Burrow R, Dumontier C, Hillyard A. A practical radiographic comparison of short board technique and Kendrick Extrication Device. Ann Emerg Med. 1989;18:943–946. 28. Graziano AF, Scheidel EA, Cline JR, Baer LJ. A radiographic comparison of prehospital cervical immobilization methods. Ann Emerg Med. 1987;16:1127–1131. 29. Chandler DR, Nemejc C, Adkins RH, Waters RL. Emergency cervical-spine immobilization. Ann Emerg Med. 1992;21:1185–1188.

Quinn et al 30. Cohen A, Bosshard R, Yeo JD. A new device for the care of acute spinal injuries: the Russell Extrication Device (RED). Paraplegia. 1990;28:151–157. 31. Boissy P, Shrier I, Briere S, et al. Effectiveness of cervical spine stabilization techniques. Clin J Sport Med. 2011;21:80–88. 32. Horodyski M, Conrad BP, Del Rossi G, DiPaola CP, Rechtine G.R. 2nd. Removing a patient from the spine board: is the lift and slide safer than the log roll? J Trauma. 2011;70:1282–1285. 33. Del Rossi G, Heffernan TP, Horodyski M, Rechtine GR. The effectiveness of extrication collars tested during the execution of spine-board transfer techniques. Spine J. 2004;4:619–623. 34. Hauswald M, Ong G, Tandberg D, Omar Z. Out-ofhospital spinal immobilization: its effect on neurologic injury. Acad Emerg Med. 1998;5:214–219. 35. McSwain NE Jr. Spine management skills. PHTLS: Prehospital Trauma Life Support. 2nd ed. Akron, OH: Educational Direction; 1990:225–256. 36. Horodyski M, DiPaola CP, Conrad BP, Rechtine 2nd GR. Cervical collars are insufficient for immobilizing an unstable cervical spine injury. J Emerg Med. 2011;41: 513–519. 37. Holla M. Value of a rigid collar in addition to head blocks: a proof of principle study. Emerg Med J. 2012;29:104– 107. 38. Podolsky S, Baraff LJ, Simon RR, Hoffman JR, Larmon B, Ablon W. Efficacy of cervical spine immobilization methods. J Trauma. 1983;23:461–465. 39. Lador R, Ben-Galim P, Hipp JA. Motion within the unstable cervical spine during patient maneuvering: the neck pivot-shift phenomenon. J Trauma. 2011;70:247–251. 40. Ben-Galim P, Dreiangel N, Mattox KL, Reitman CA, Kalantar SB, Hipp JA. Extrication collars can result in abnormal separation between vertebrae in the presence of a dissociative injury. J Trauma. 2010;69:447–450. 41. Craig GR, Nielsen MS. Rigid cervical collars and intracranial pressure. Intensive Care Med. 1991;17:504–505. 42. Davies G, Deakin C, Wilson A. The effect of a rigid collar on intracranial pressure. Injury. 1996;27:647–649. 43. Raphael JH, Chotai R. Effects of the cervical collar on cerebrospinal fluid pressure. Anaesthesia. 1994;49:437–439. 44. Kolb JC, Summers RL, Galli RL. Cervical collar-induced changes in intracranial pressure. Am J Emerg Med. 1999;17:135–137. 45. Mawson AR, Biundo JJ Jr, Neville P, Linares HA, Winchester Y, Lopez A. Risk factors for early occurring pressure ulcers following spinal cord injury. Am J Phys Med Rehabil. 1988;67:123–127. 46. Blaylock B. Solving the problem of pressure ulcers resulting from cervical collars. Ostomy Wound Manage. 1996;42(26–28):32–33. 30. 47. Liew SC, Hill DA. Complication of hard cervical collars in multi-trauma patients. Aust N Z J Surg. 1994;64:139–140. 48. Linares HA, Mawson AR, Suarez E, Biundo JJ. Association between pressure sores and immobilization in the

WMS Practice Guidelines for Spine Immobilization in the Austere Environment

49.

50.

51.

52.

53.

54.

55.

56.

57.

58.

59.

60.

61.

62.

63.

immediate post-injury period. Orthopedics. 1987;10: 571–573. McGrath T, Murphy C. Comparison of a SAM splintmolded cervical collar with a Philadelphia cervical collar. Wilderness Environ Med. 2009;20:166–168. Chan D, Goldberg RM, Mason J, Chan L. Backboard versus mattress splint immobilization: a comparison of symptoms generated. J Emerg Med. 1996;14:293–298. Hamilton RS, Pons PT. The efficacy and comfort of fullbody vacuum splints for cervical-spine immobilization. J Emerg Med. 1996;14:553–559. Johnson DR, Hauswald M, Stockhoff C. Comparison of a vacuum splint device to a rigid backboard for spinal immobilization. Am J Emerg Med. 1996;14:369–372. Main PW, Lovell ME. A review of seven support surfaces with emphasis on their protection of the spinally injured. J Accid Emerg Med. 1996;13:34–37. Lovell ME, Evans JH. A comparison of the spinal board and the vacuum stretcher, spinal stability and interface pressure. Injury. 1994;25:179–180. Luscombe MD, Williams JL. Comparison of a long spinal board and vacuum mattress for spinal immobilisation. Emerg Med J. 2003;20:476–478. Ellerton J, Tomazin I, Brugger H, Paal P. International Commission for Mountain Emergency Medicine. Immobilization and splinting in mountain rescue. Official Recommendations of the International Commission for Mountain Emergency Medicine, ICAR MEDCOM, Intended for Mountain Rescue First Responders, Physicians, and Rescue Organizations. High Alt Med Biol. 2009;10:337–342. Anderson PA, Muchow RD, Munoz A, Tontz WL, Resnick DK. Clearance of the asymptomatic cervical spine: a metaanalysis. J Orthop Trauma. 2010;24:100–106. Hoffman JR, Mower WR, Wolfson AB, Todd KH, Zucker MI. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. National Emergency X-Radiography Utilization Study Group. N Engl J Med. 2000;343:94–99. Domeier RM, Evans RW, Swor RA, Rivera-Rivera EJ, Frederiksen SM. Prospective validation of out-of-hospital spinal clearance criteria: a preliminary report. Acad Emerg Med. 1997;4:643–646. Domeier RM, Frederiksen SM, Welch K. Prospective performance assessment of an out-of-hospital protocol for selective spine immobilization using clinical spine clearance criteria. Ann Emerg Med. 2005;46:123–131. Burton JH, Dunn MG, Harmon NR, Hermanson TA, Bradshaw JR. A statewide, prehospital emergency medical service selective patient spine immobilization protocol. J Trauma. 2006;61:161–167. Burton JH, Harmon NR, Dunn MG, Bradshaw JR. EMS provider findings and interventions with a statewide EMS spine-assessment protocol. Prehosp Emerg Care. 2005;9:303–309. Bandiera G, Stiell IG, Wells GA, et al. The Canadian C-spine rule performs better than unstructured physician judgment. Ann Emerg Med. 2003;42:395–402.

251

64. Dickinson G, Stiell IG, Schull M, et al. Retrospective application of the NEXUS low-risk criteria for cervical spine radiography in Canadian emergency departments. Ann Emerg Med. 2004;43:507–514. 65. Kerr D, Bradshaw L, Kelly AM. Implementation of the Canadian C-spine rule reduces cervical spine x-ray rate for alert patients with potential neck injury. J Emerg Med. 2005;28:127–131. 66. Stiell IG, Clement CM, O’Connor A, et al. Multicentre prospective validation of use of the Canadian C-Spine Rule by triage nurses in the emergency department. CMAJ. 2010;182:1173–1179. 67. Stiell IG, Grimshaw J, Wells GA, et al. A matched-pair cluster design study protocol to evaluate implementation of the Canadian C-spine rule in hospital emergency departments: Phase III. Implement Sci. 2007;2:4. 68. Stiell IG, Wells GA, Vandemheen KL, et al. The Canadian C-spine rule for radiography in alert and stable trauma patients. JAMA. 2001;286:1841–1848. 69. Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349:2510–2518. 70. Vaillancourt C, Charette M, Kasaboski A, Maloney J, Wells GA, Stiell IG. Evaluation of the safety of C-spine clearance by paramedics: design and methodology. BMC Emerg Med. 2011;11:1–11. 71. Vaillancourt C, Stiell IG, Beaudoin T, et al. The out-ofhospital validation of the Canadian C-Spine Rule by paramedics. Ann Emerg Med. 2009;54:663–671. 72. Konstantinidis A, Plurad D, Barmparas G, et al. The presence of nonthoracic distracting injuries does not affect the initial clinical examination of the cervical spine in evaluable blunt trauma patients: a prospective observational study. J Trauma. 2011;71:5285–5232 73. Blair JA, Possley DR, Petfield JL, Schoenfeld AJ, Lehman RA, Hsu JR. Skeletal Trauma Research Consortium (STReC). Military penetrating spine injuries compared with blunt. Spine J. 2012;12:762–768. 74. Inaba K, Barmparas G, Ibrahim D, et al. Clinical examination is highly sensitive for detecting clinically significant spinal injuries after gunshot wounds. J Trauma. 2011;71:523–527. 75. Rhee P, Kuncir EJ, Johnson L, et al. Cervical spine injury is highly dependent on the mechanism of injury following blunt and penetrating assault. J Trauma. 2006;61: 1166–1170. 76. Stuke LE, Pons PT, Guy JS, Chapleau WP, Butler FK, McSwain NE. Prehospital spine immobilization for penetrating trauma—review and recommendations from the Prehospital Life Support Executive Committee. J Trauma. 2011;71:763–769. 77. DuBose J, Teixeira PGR, Hadjizacharia P, et al. The role of routine spinal imaging and immobilisation in asymptomatic patients after gunshot wounds. Injury. 2009;40:860–863. 78. Lustenberger T, Talving P, Lam L, et al. Unstable cervical spine fracture after penetrating neck injury: a rare entity in an analysis of 1,069 patients. J Trauma. 2011;70:870–872.

252 79. Butler FK Jr, Hagmann J, Butler EG. Tactical combat casualty care in special operations. Mil Med. 1996; 161(suppl):3–16. 80. Butler FK, Giebner S, McSwain N, Pons P, eds. Prehospital Trauma Life Support Manual: Military Version. 2011 7th ed. St. Louis, MO: Mosby; 591.

Quinn et al 81. Clinical Effectiveness Committee, The College of Emergency Medicine. Guideline on the management of alert, adult patients with potential cervical spine injury in the Emergency Department. Available at: http://www.resusme.em.extreme member.com/wp-content/uploads/2011/02/CEM5718-cervicalspine-full-guideline.pdf. Accessed March 19, 2013.